Possibility to remove token by value

Returns null if nothing was removed. Value if single token was removed. Number of tokens if multiple tokens were removed.
```
$input.tokenizer('remove', 'YOLO'); // => null
$input.tokenizer('push', 'YOLO');
$input.tokenizer('remove', 'YOLO'); // => 'YOLO'
$input.tokenizer('push', 'YOLO');
$input.tokenizer('push', 'YOLO');
$input.tokenizer('remove', 'YOLO'); // => 2
```